Aquatic resistance ball filled with non-toxic granular material

ABSTRACT

An aquatic resistance ball is provided that comprises a containment skin substantially filled with, and surrounding, a non-toxic soluble material such as salt. The containment skin is made of a water resistant material and the bulk density of the contents of the containment skin is greater than 1 g/cm3. The resistance ball is substantially spherical, ovoid or tubular in shape.

The present invention relates to resistance balls.

Resistance balls, such as medicine balls or other weighted balls are well known in the art for their use in sports training and remedial physical therapy.

Such balls commonly consist of a skin filled with an inert granular material such as sand and are available in a range of weights.

It is the purpose of the present invention to provide a resistance ball that is particularly suited to use in an aquatic environment.

According to a first aspect of the present invention there is provided an aquatic resistance ball comprising a containment skin substantially filled with, and surrounding, a non-toxic granular soluble material, wherein the containment skin comprises a water resistant material and wherein the bulk density of the resistance ball is greater than the 1 g/cm³.

By non toxic it is meant that, in the case that the resistance ball were to rupture when in use, the material in the resistance ball, if dissolved in the water, would not be harmful to anyone in the water. This can be further defined as the material in a single resistance ball, if dissolved in a volume of water of 1.5 m³ would not be harmful to the health of a human for a contact time up to 30 minutes. Essentially this means that if all the material was to dissolve and there were little water movement, the exposure of a human to the localised concentration of the material in the water will have no ill effect on the person.

By using a soluble material the current invention presents a great improvement over the prior art when used in an aquatic environment, such as a swimming pool. If a ball ruptures in use then the material therein that is released into the pool will slowly dissolve therein. As chemical balances of swimming pools are constantly being monitored then the increase in concentration of the particular material released can be returned to normal over time. It will be appreciated that as the material is non toxic, the solution of some of that material into the volume of water in a pool would not render it unsafe and the pool could continue to be used. If a non soluble material was to be used then this would eventually be drawn through the cleaning systems of the pool and would accumulate at the lowest point, possibly contributing to blockages. Furthermore, if a non soluble material such as sand were to be passes through pumps of the cleaning system this could accelerate their wear.

By having a bulk density greater than 1 g/cm³ this results in a ball that is negatively buoyant in water.

Preferably the containment skin is substantially spherically shaped, although it will be appreciated that other shapes, for example ovoid or tubular, may equally be used.

Preferably the containment skin is sealed. In this way there is no possibility for water ingress into the resistance ball which would alter its bulk density. Optionally a valve may be provided in the containment skin to allow the addition or removal of gas therefrom to alter the balls bulk density. By altering the density of the ball, and therefore its speed of movement in water a user's proprioception can be improved.

Preferably the non toxic soluble material comprises salt, more preferably the non toxic soluble material is NaCl.

In one arrangement the aquatic resistance ball may further comprise an inflatable bladder within the containment skin. The inflatable bladder is preferably inflatable via a valve in the containment skin. This enables the bulk density of the resistance ball to be modified after it has been filled with salt so as to achieve a resistance ball that will sink through water at a required rate.

In an alternative arrangement the aquatic resistance ball may comprise a second outer skin surrounding the containment skin so as to form a cavity therebetween. The cavity has a valve leading thereinto to enable the introduction of gas into said cavity. By introducing air into the cavity the bulk density of the ball can be reduced so as to change its buoyancy.

By changing the buoyancy of the balls they can be made to fall through the water at differing rates. This enables a beginner using the balls to start at a slow pace and increase the speed at which the ball sinks as they increase their co-ordination and/or strength and skill level. The different buoyancy and weight of the ball or balls enables them to be used as a quantitative tool for performance and rehabilitation evaluation.

Preferably the containment skin is a polymer material, more preferably the containment skin is elastomeric.

According to a second aspect of the invention there is provided a method of making an aquatic resistance ball comprising: forming a substantially spherical containment skin having an inlet from a water resistant material; filling said containment skin with a non toxic soluble material via said inlet; sealing said inlet such that, when sealed, the bulk density of the contents of the containment skin is greater than the 1 g/cm³.

Preferably filling said containment skin with a non toxic soluble material via said inlet comprises filling the containment skin with salt, more preferably filling the containment skin with NaCl.

The method may further comprise forming an inflatable bladder internally within the containment skin. The method may comprise, after sealing the inlet, inflating the bladder via a bladder inlet valve located in the containment skin to modify the internal volume of the containment skin to alter the bulk density to achieve a desired bulk density.

Alternatively the method may comprise placing the containment skin inside an outer skin to create an inflatable cavity therebetween.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is one embodiment of a resistance ball according to the invention;

FIG. 2 is another embodiment of a resistance ball according to the invention;

FIG. 3 is another embodiment of a resistance ball according to the invention; and

FIG. 4 is a flow chart of a method of manufacturing a resistance ball of the invention.

Referring to FIG. 1 a resistance ball 10 of the invention is shown. The ball 10 has a containment skin 12 which is made of a water resistant polymer material, for example PVC. The ball 10 is substantially filled with granular NaCl 14. The point through which the ball 10 is filled is sealed with a seal 16 which is preferably of the same material as the ball 10. The ball can be used in underwater co-ordination training, for example practicing “keepy uppy”, otherwise known as ball juggling in which a ball is kept in the air (or in this case in the water) by haptic perception striking it with the feet, knees, thighs etc. which concomitantly is a form of proprioceptive and balance training.

By practicing this skill underwater greater concentration and co-ordination are achieved via resistance training as the water resists the passage of the limbs therethrough. As the practice will be performed in a swimming pool the users head will be above water so the player will have to take into consideration the effect of refraction of light as it passes through the water surface when trying to strike the ball. This combined with the distraction created by the general movement of the water surface results in great concentration and co-ordination to be needed.

In addition to being used underwater the ball can also be used at water surface level or above water for pool based exercises. It will be appreciated that as with traditional exercise weights the ball may be provided as a set with different balls in the set having different weights and/or different buoyancies.

By using salt, which is a non toxic, soluble, substance in the ball, in the event of a rupture in the containment skin the release of the salt into a pool environment will not be a cause for concern, either for the health of individuals using the pool or for the pool pumps and cleaning systems themselves. In particular no special cleaning will be required to remove the materials (apart from, of course, the ruptured containment skin) from the pool.

Optionally the ball may be provided with a valve 36 to allow for gas, for example air, to be added or removed from the containment skin to change the bulk density of the ball. Increasing or decreasing the balls negative buoyancy may be necessary, especially when used in a thalassotherapy pool (salt water).

Referring to FIG. 2 a variation of the ball of FIG. 1 is shown. In this example the ball 10 a has a bladder 18 located therein, the bladder being connected by a passage 20 to a valve 22 in the outer surface of the ball 10 a. It will be appreciated that the size of the bladder shown is merely for illustrative purposes and is not to scale. The space between the bladder 18 and the containment skin 12 is filled with salt 14. Air (or other gas) can be added to the bladder 18 via the valve 22 to partially inflate it. This additional air changes the bulk density of the ball as it changes the air to salt ratio therein. Unlike in air wherein, unless the ball is of a similar density to air, changes in the density of a ball will not effect its performance, in an underwater environment, due to the density of the water, changes to the density of the ball by injection of air thereinto are sufficient to effect the speed at which the ball will sink through the water. Accordingly the ball can be adapted to suit a particular individuals training need. As the individual becomes more practiced and more skilled in using the ball the density can be increased so that they will have to work faster to maintain the ball suspended in the water and prevent it falling to the bottom.

Referring to FIG. 3 a further embodiment of the ball 10 b is shown. In this embodiment the containment skin 12, filled with the salt 14 and sealed by seal 16 is surrounded by an outer skin 38. The containment skin 12 and the outer skin 38 form a cavity 40 therebetween that can have gas, for example air, introduced into it via valve 42 so as to alter the bulk density of the ball 10 b. Although shown as completely separate, it will be appreciated that the containment skin 12 and the outer skin 38 may be joined to one another by, for example, ribs extending therebetween. In this embodiment it will be appreciated that the outer skin gives further protection against rupture of the containment skin.

Referring now to FIG. 4 a flow chart of a method of manufacturing a ball of the invention is shown. In the first step 24 a containment skin is formed, from a water resistant material, which has an inlet. In the next step 26 the containment skin is filled with a non toxic soluble material, such as NaCl via the inlet, and finally in the last step 28 the inlet is sealed such that the bulk density of the contents of the containment skin is greater than the 1 g/cm³. Prior to sealing, a pump may be applied to the inlet to extract any excess air therefrom 30.

Optionally the method may include the step 32 an inflatable bladder may be formed internally within, or around, the containment skin. The bladder may be formed separately and inserted into the containment skin, or the containment skin inserted into the bladder. Alternatively the containment skin may be formed around the bladder or the bladder may be formed around the containment skin. After sealing the inlet the method may include a further step 34 in which the bladder may be inflated via a bladder inlet valve to modify the internal volume of the ball to alter the bulk density to achieve a desired bulk density. It will be appreciated that the steps shown in the dashed line are optional steps. 

1. An aquatic resistance ball comprising a containment skin surrounding and substantially filled with a non-toxic soluble granular material, wherein the containment skin comprises a water resistant material and wherein a bulk density of contents of the containment skin is greater than the 1 g/cm3.
 2. The aquatic resistance ball according to claim 1, wherein the containment skin is substantially spherical, ovoid, or tubular shaped.
 3. The aquatic resistance ball according to claim 1 wherein the containment skin is sealed.
 4. The aquatic resistance ball according to claim 1 wherein the non-toxic soluble granular material comprises salt.
 5. The aquatic resistance ball according to claim 4 wherein the non-toxic granular soluble material is sodium chloride (NaCl).
 6. Theme aquatic resistance ball according to claim 1 further comprising an inflatable bladder within the containment skin.
 7. The aquatic resistance ball according to claim 6 wherein the inflatable bladder is inflatable via a valve in the containment skin.
 8. The aquatic resistance ball according to claim 1 further comprising an outer skin surrounding the containment skin forming a cavity therebetween.
 9. The aquatic resistance ball according to claim 8, wherein the cavity has a valve leading thereinto to enable introduction of gas into the cavity.
 10. The aquatic resistance ball according to claim 1, wherein the containment skin is a polymer material.
 11. The aquatic resistance ball according to claim 10, wherein the containment skin is elastomeric.
 12. A method of making an aquatic resistance ball comprising: forming a containment skin having an inlet from a water resistant material; filling the containment skin with a non-toxic soluble material via the inlet such that the containment skin substantially surrounds the non-toxic soluble material; and sealing the inlet such that, when sealed, a bulk density of contents of the resistance ball is greater than 1 g/cm3.
 13. The method according to claim 12, wherein forming the containment skin comprises forming the containment skin in a substantially spherical, ovoid or tubular shape.
 14. The method according to claim 12, wherein filling the containment skin with a non-toxic soluble material via the inlet comprises filling the containment skin with salt.
 15. The method according to claim 14, wherein filling the containment skin with salt comprises filling the containment skin with sodium chloride (NaCl).
 16. The method according to claim 12 further comprising forming an inflatable bladder internally within the containment skin.
 17. The method according to claim 14 further comprising, after sealing the inlet, inflating the bladder via a bladder inlet valve located in the containment skin to modify an internal volume of the resistance ball thereby altering a bulk density to achieve a desired bulk density.
 18. The method according to claim 12 further comprising forming an outer skin around the containment skin to form a cavity therebetween.
 19. The method according to claim 18 further comprising, after sealing the inlet, inflating the cavity via a cavity valve located in the outer skin to modify an internal volume of the resistance ball thereby altering a bulk density to achieve a desired bulk density. 